Temperature and precipitation in Northeast China during the last 150 years: relationship to large-scale climatic variability

摘要

The analysis of two historical time series of temperature and precipitationin Northeast China, spanning, respectively, 1870–2004 and 1841–2004,performed by continuous wavelet transform and other classical and advancedspectral methods, is presented here. Both variables show a particular trendand oscillations of about 85, 60, 35 and 20 years that are highlysignificant, with a phase opposition at the centennial scale and at the20-year scale. The analysis of the four temperature series relative to singleseasons shows that the 20-year cycle is typical of the summer monsoon season,while the 35-year cycle is most evident in winter. The cycles of~ 60 years and longer are present in all seasons. The centennialvariation of temperature and precipitation describes well the 1970–1980transition between a period of relatively strong East Asian Summer Monsoon(EASM), corresponding to high precipitation and relatively cool temperaturesin Northeast China, and a conditions of weak EASM (low precipitation and warmtemperatures). The connection of the detected local variations withlarge-scale climatic variability is deduced from the comparison withdifferent climatic records (Northern Hemisphere temperature, Pacific DecadalOscillation and Atlantic Multidecadal Oscillation indexes).